Display device

ABSTRACT

According to one embodiment, a display device includes a first substrate, a second substrate, a sealant, a liquid crystal layer, an organic insulating film, an alignment film and an inorganic insulating film. The second substrate is opposed to the first substrate. The sealant attaches the first substrate and the second substrate to each other. The liquid crystal layer is arranged between the first substrate and the second substrate. The organic insulating film, the alignment film and the inorganic insulating film are provided on the first substrate. The alignment film contacts the liquid crystal layer. The inorganic insulating film is located between the alignment film and the organic insulating film. At least pan of the alignment film contacts the organic insulating film.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. application Ser.No. 15/876,254, filed Jan. 22, 2018, which is based upon and claims thebenefit of priority from Japanese Patent Application No. 2017-017588,filed Feb. 2, 2017, the entire contents of both of which areincorporated herein by reference.

FIELD

Embodiments described herein relate generally to a display device.

BACKGROUND

A liquid crystal display device in general includes a pair ofsubstrates, a sealant which attaches the substrates to each other, aliquid crystal layer interposed between the substrates, and an alignmentfilm which aligns liquid crystal molecules included in the liquidcrystal layer. If a frame area surrounding a display area issufficiently broad, the alignment film is formed on the inner side fromthe sealant. In the recent liquid crystal display device in which theframe is narrowed, the alignment film may be formed up to a locationoverlapping the sealant in some cases.

Embodiments aim to provide a display device which can display ahigh-quality image.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic plan view of the structure of a display devicecommon in the embodiments.

FIG. 2 is a sectional view of the structure of a display area shown inFIG. 1.

FIG. 3 is a sectional view of the structure of an edge of a firstsubstrate according to the first embodiment.

FIG. 4 is a sectional view of a comparative example of the firstembodiment shown in FIG. 3.

FIG. 5 is a sectional view of the structure of an edge of a firstsubstrate according to the second embodiment.

FIG. 6 is a sectional view of the structure of an edge of a firstsubstrate according to the third embodiment.

DETAILED DESCRIPTION

In general, according to one embodiment, a display device includes afirst substrate, a second substrate, a sealant, a liquid crystal layer,an organic insulating film, an alignment film and an inorganicinsulating film. The second substrate is opposed to the first substrate.The sealant attaches the first substrate and the second substrate toeach other. The liquid crystal layer is arranged between the firstsubstrate and the second substrate. The organic insulating film, thealignment film and the inorganic insulating film are provided on thefirst substrate. The alignment film contacts the liquid crystal layer.The inorganic insulating film is located between the alignment film andthe organic insulting film. At least part of the alignment film contactsthe organic insulating film.

Embodiments will be described hereinafter with reference to theaccompanying drawings. Incidentally, the disclosure is merely anexample, and proper changes within the spirit of the invention, whichare easily conceivable by a skilled person, are included in the scope ofthe invention as a matter of course. In addition, in some cases, inorder to make the description clearer, the widths, thicknesses, shapes,and the like of the respective parts are schematically illustrated inthe drawings, compared to the actual modes. However, the schematicillustration is merely an example, and adds no restrictions to theinterpretation of the invention. Besides, in the specification anddrawings, the structural elements having functions, which are identicalor similar to the functions of the structural elements described inconnection with preceding drawings, are denoted by like referencenumerals, and an overlapping detailed description is omitted unlessotherwise necessary.

Further, in this specification, expressions such as “α includes A, B orC”, “α includes any one of A, B and C” “α is selected from a groupconsisting of A, B and C” do not exclude a case where α includescombinations of A, B and C unless otherwise specified. Still further,these expressions do not exclude a case where α includes other elements.

A display device DSP, which is a liquid crystal display device, will bedisclosed as an example of the display device in the followingdescription. The display device DSP can be used in various devices suchas smartphones, tablet computers, mobile phones, personal computers,television receivers, in-vehicle devices, game consoles and wearabledevices. The display device DSP has the function of operating in a lowfrequency driving mode of reducing circuit consumption power undercircumstances where low power consumption is valued highly.

Firstly, the structure common in the embodiments will be described withreference to FIGS. 1 and 2. FIG. 1 is a schematic plan view of thestructure of the display device DSP. The display device DSP includes adisplay panel (liquid crystal cell) PNL and an illumination device(backlight) BL which emits light to the display panel PNL, for example.The display panel PNL may be a reflective display panel which displaysan image by selectively reflecting light entering the display surface ofthe display panel PNL. If the display panel PNL is a reflective displaypanel, the illumination device BL may be omitted.

In the following description, a view from the display surface to theback surface of the display panel PNL as shown in FIG. 1 will be definedas planar view. Further, a first direction X a second direction Y and athird direction Z will be defined as shown in FIG. 1. The firstdirection X is a direction along the short sides of the display panelPNL, for example. The second direction Y is a direction along the longsides of the display panel PNL, for example. The third direction Z isthe thickness direction of the display panel PNL, for example. In theexample shown in FIG. 1, the first, second and third directions X, Y andZ perpendicularly cross each other. The first, second and thirddirections X, Y and Z may cross each other at another angle.

The display panel PNL includes a first substrate (array substrate) SUB1,a second substrate (counter-substrate) SUB2, a sealant 3 and a liquidcrystal layer LC. The second substrate SUB2 is opposed to the firstsubstrate SUB1 in the third direction Z. The first substrate SUB1 islarger than the second substrate SUB2 in the second direction Y and hasa terminal area NDAt exposed from the second substrate SUB2.

Further, the first substrate SUB1 has first, second, third and fourthsides E1, E2, E3 and E4. For example, the first and third sides E1 andE3 are lire short sides in the first direction X, and the second andfourth sides E2 and E4 are the long sides in the second direction Y.

The sealant 3 is formed of an organic material such as acrylic resin orepoxy resin. Further, the sealant 3 corresponds to a portion shown byrising diagonal lines shown in FIG. 1 and attaches the first substrateSUB1 and the second substrate SUB2 to each other. The liquid crystallayer LC is sealed on the inner side from the sealant 3 between thesecond substrate SUB2 and the first substrate SUB1.

Further, the display panel PNL has a display area DA which displays animage, and a non-display area (frame area) NDA which surrounds thedisplay area DA. A plurality of sub-pixels SPX are arranged in an m-by-nmatrix in the display area DA. For example, a pixel PX which can performcolor display can be formed of the combination of three sub-pixels SPXcorresponding to red (R), green (G) and blue (B). The pixel PX is notlimited to this example but may include a sub-pixel SPX corresponding toanother color such as while or may include sub-pixels SPX correspondingto the same color.

The non-display area NDA includes first, second, third and fourthnon-display areas NDA1, NDA2, NDA3 and NDA4. The first non-display areaNDA1 is located between the display area DA and the first side E1.Similarly, the second non-display area NDA2 is located between thedisplay area DA and the second side E2. The third non-display area NDA3is located between the display area DA and the third side E3. The fourthnon-display area NDA4 is located between the display area DA and thefourth side E4. The first non-display area NDA1 includes the terminalarea NDAt.

Further, the display device DSP includes a control module CTR, a scandriver GD and an image driver SD. In the example shown in FIG. 1, thedisplay device DSP includes two scan drivers GD (GD1 and GD2). One ofthe two scan drivers GD1 and GD2 may be omitted.

The scan driver GD1 is formed on the first substrate SUB1 in the secondnon-display area NDA2. Similarly, the scan driver GD2 is formed on thefirst substrate SUB1 in the fourth non-display area NDA4. The scandrivers GD1 and GD2 and the image driver SD are examples of the drivercircuit for image display, and can be formed together with a switchingelement SW of the sub-pixel SPX which will be described later in thesame manufacturing process, for example.

The control module CTR is provided in the terminal area NDAt, forexample. The image driver SD is formed on the inner side from theterminal area NDAt in the first non-display area NDA1, for example. Theimage driver SD may be formed as an IC chip on the first substrate SUB1instead. The image driver SD may be provided in the control module CTR.The control module CTR and the image driver SD may be provided on anexternal circuit board connected to the display panel PNL.

Further, the display panel PNL includes a plurality of scanning signallines GL (GL1, GL2, GL3, GL4, . . . , GLm+1) and a plurality of imagesignal lines SL (SL1, SL2, SL3, SL4, . . . , SLn+1) crossing thescanning signal lines GL in the display area DA. Still further, thedisplay panel PNL includes a trap power supply line GLt in thenon-display area. The trap power supply line GLt is arranged around thedisplay area DA and is connected to the control module CTR.

The scanning lines GL extend in the first direction X and are arrangedin the second direction Y. The scanning lines GL are connected the scandrivers GD. In the example shown in FIG. 1, the odd-numbered scanninglines GL1, GL3, . . . , GLm−1 of the scanning signal lines GL areconnected to the scan driver GD1, and the even-numbered scanning signallines GL2, GL4, . . . , GLm of the scanning signal lines GL areconnected to the scan driver GD2. The scan drivers GD1 and GD2 supply ascanning signal to the corresponding scanning signal lines GL.

The image signal lines SL extend in the second direction Y and arearranged in the first direction X. The image signal lines SL areconnected to the image driver SD. The image driver SD supplies an imagesignal to the image signal lines SL.

The sub-pixels SPX are areas enclosed with the scanning signal lines GLand the imaging signal lines SL. Each of the sub-pixels SPX includes theswitching element SW, a pixel electrode PE and a common electrode CE.The switching element SW is formed of a thin-film transistor (TFT), forexample, and is electrically connected to the scanning signal line GL,the image signal line SL and the pixel electrode PE. The commonelectrode CE is formed over the sub-pixels SPX. The pixel electrode PEis connected to the switching element SW and is opposed to the commonelectrode CE.

When a scanning signal is supplied to the scanning signal line GLcorresponding to a switching element SW, the image signal line SL andthe pixel electrode PE corresponding to this switching element SW areelectrically connected to each other, and an image signal of the imagesignal line SL is supplied to the pixel electrode PE. The pixelelectrode PE forms an electric field between the pixel electrode PE andthe common electrode CE and changes alignment of the liquid crystalmolecules of the liquid crystal layer LC. Storage capacitance CS isformed between the common electrode CE and the pixel electrode PE, forexample.

The control module CTR controls the operations of the scan drivers GDand the image driver SD. Further, the control module CTR applies acommon voltage to the common electrode CE and applies a trap voltagehaving a potential lower or higher than the common voltage to the trappower supply line GLt. The control module CTR may be formed on anexternal circuit hoard connected to the terminal area NDAt and maycontrol the reflective members from the external circuit board.

Further, the control module CTR not only has a normal driving functionbut also has a low frequency driving function of reducing drive power.The low frequency driving is a driving mode of setting the framefrequency of the display device DSP to a frame frequency lower than thatof a normal driving mode (for example, 60 Hz). In the low frequencydriving, the frame frequency of the display device DSP is 40 Hz or lessand is assumed to be 30 Hz or less or 15 Hz or less, for example. Theframe frequency corresponds to the frequency of writing an image signalto the sub-pixel SPX. If the frame frequency is reduced, the frequencyof writing an image signal to the sub-pixel SPX is reduced, and thepower consumption of the circuits can be reduced, accordingly.

FIG. 2 is a sectional view of the display device DSP in the display areaDA in the first direction X. The display panel PNL further includes afirst polarizer PL1 and a second polarizer PL2. The first polarizer PL1is arranged on the back surface side of the display panel PNL betweenthe backlight BL and the display panel PNL. The second polarizer PL2 isarranged on the display surface side of the display panel PNL.

In the example shown in FIG. 2, the display panel PNL has a structureconforming to a display mode of mainly using a lateral electric fieldsubstantially parallel to an X-Y plane. The display panel PNL may have astructure conforming to a display mode using a longitudinal electricfield perpendicular to the X-Y plane, a display mode using an obliqueelectric field inclined to the X-Y plane, or a display mode using acombination thereof. The display panel PNL of the display mode using thelateral electric field is suitable for the low frequency driving becausethe display panel PNL of the display mode using the lateral electricfield is excellent in voltage holding properties as compared to that ofthe display mode using the longitudinal electric field.

As described above, the first substrate SUB1 includes the scanningsignal line GL, the image signal line SL, and the switching element SW,the pixel electrode PE, the common electrode CE and the trap powersupply line GLt. The first substrate SUB1 further includes a firstinsulating base 10, a first insulating film 11, a second insulating film12, a third insulating film 13, a fourth insulating film 14, a fifthinsulating film 15 and a first alignment film AL1. The switching elementSW includes a semiconductor layer SC and a relay electrode SLr. The trappower supply line GLt is connected to a trap electrode TE. A voltageapplied to the trap power supply line GLt is applied to the trapelectrode TE.

As shown in FIG. 2, the semiconductor layer SC is formed on the firstinsulating base 10. Another insulating film may be interposed betweenthe semiconductor layer SC and the first insulating base 10. The firstinsulating film 11 covers the semiconductor layer SC and the firstinsulating base 10. The scanning signal line GL and the trap powersupply line GLt are formed on the first insulating film 11. The scanningsignal line GL and the trap power supply line GLt can be formed in thesame manufacturing process. The second insulating film 12 covers thescanning signal line GL, the trap power supply line GLt and the firstinsulating film 11.

The image signal line SL and the relay electrode (a source electrode ora drain electrode) SLr are formed on the second insulating film 12 andcontact the semiconductor layer SC via contact notes CH1 and CH2. Theimage signal line SL and the relay electrode SLr can be formed in thesame manufacturing process. The third insulating film 13 covers theimage signal line SL, the relay electrode SLr and the second insulatingfilm 12. The fourth insulating film 14 covers the third insulating film13. The common electrode CE is formed on the fourth insulating film 14.The fifth insulating film 15 covers the common electrode CE and thefourth insulating film 14. The fifth insulating film 15 functions as aninterlayer insulating film which insulates the pixel electrode PE andthe common electrode CE from each other.

The pixel electrode PE is formed on the filth insulating film 15 andcontacts the relay electrode SLr via a contact hole CH3. The trapelectrode TE is formed on the fifth insulating film 15 and contacts thetrap power supply line GLt via a contact hole CH4. The pixel electrodePE and One trap electrode TE are examples of the transparent conductivefilm and can be formed in the same manufacturing process. The trapelectrode TE is an electrode to which a voltage applied from the trappower supply line GLt (the same voltage as a gate low voltage whichturns off the switching element SW, for example) is applied and whichholds ions generated from the sealant 3 and the liquid crystal layer LC.

The pixel electrode PE may be formed below the fifth insulating film 15,and the common electrode CE may be formed on the fifth insulating film15. In that case, the trap electrode TE and the common electrode CE maybe formed in the same manufacturing process. The common electrode CE isanother example of the transparent conductive film. The first alignmentfilm AL1 covers the pixel electrode PE, the trap electrode TE and thefifth insulating film 15 and contacts the liquid crystal layer LC. Thefirst alignment film AL1 aligns the liquid crystal molecules of theliquid crystal layer LC in a state where a voltage is not applied to thepixel electrode PE.

A translucent and insulating, glass base or resin base can be used asthe first insulating base 10, for example. The common electrode CE, thepixel electrode PE and the trap electrode TE can be formed of atransparent conductive material such as indium tin oxide (ITO) or indiumzinc oxide (IZO). The scanning signal line GL and the trap power supplyline GLt, and the image signal line SL and the relay electrode SLr aremetal lines having a single layer structure or a slacked layerstructure, for example.

The first alignment film AL1 can be formed by applying polyimide resin,etc., by ink-jet priming, flexographic printing, etc., for example. Thefirst alignment film AL1 may extend outside the sealant 3 (shown in FIG.3). The first alignment film AL1 has a thickness of 100 nm, for example.

The fourth insulating film 14 is an organic insulating film formed ofphotosensitive resin such as acrylic resin, for example, and extends tothe edges of the first substrate SUB1. The fourth insulating film 14 hasthe function of leveling unevenness of the switch element SW and isthicker than the first, second, third and fifth insulating films 11, 12,13 and 15 and the first alignment film AL1. The fourth insulating film14 may be referred to as an organic leveling film. For example, thethickness of the fourth insulating film 14 should preferably be tenormore times the thickness of the first alignment film AL1. In this way,moisture absorption properties and surface flatness which will bedescribed later can be ensured.

The fourth insulating film 14 is formed by photolithography, forexample, and the thickness is adjusted on a portion-to-portion basis bymulti-tone processing such as half-tone processing (shown in FIG. 6). Aportion of the fourth insulating film 14 which is not subjected to themulti-tone processing has a thickness of 3 μm, for example. A portion ofthe fourth insulating film 14 which is subjected to the half-toneprocessing has a thickness of 1.5 μm, for example.

The first, second, third and fifth insulating films 11, 12, 13 and 15are an inorganic insulating film of silicon oxide, silicon nitride,alumina, etc. The first, second, third and fifth insulating films 11,12, 13 and 15 are impervious to water. On the other hand, the firstalignment film AL1 and the fourth insulating film 14 formed of anorganic material is slightly pervious to water.

The second substrate SUB2 includes a second insulating base 20, alight-shielding layer (black matrix) 21, a color filter layer 22, anovercoat layer 23 and a second alignment film AL2. The second insulatingbase 20 can be formed of the same material as that of the firstinsulating base 10. The second alignment film AL2 can be formed of thesame material as that of the first alignment film AL1.

As shown in FIG. 2, the light-shielding layer 21 is formed below thesecond insulating base 20. The color filter layer 22 covers thelight-shielding layer 21 and the second insulating base 20. Thelight-shielding layer 21 is located in the non-display area NDA inplanar view. Further, the light-shielding layer 21 is located directlyabove metal lines such as the scanning signal line GL, the image signalline SL and the relay electrode SLr, and the sub-pixels PSX arepartitioned by the light-shielding layer 21 in the display area DA. Thecolor filter layer 22 is opposed to the pixel electrode PE and partiallyoverlaps the light-shielding layer 21.

The color filler layer 22 includes a red filler layer, a green filterlayer, a blue filter layer, etc., arranged in accordance with thesub-pixels SPX. The overcoat layer 23 covers the color filter layer 22.The second alignment film AL2 covers the overcoat layer 23 and contactsthe liquid crystal layer LC.

First Embodiment

Next, the display device DSP of the first embodiment will be describedwith reference to FIGS. 3 and 4. FIG. 3 is a sectional view of thestructure of the display device DSP in the fourth non-display area NDA4of the first embodiment. The cross-section structures in the first,second and third non-display areas NDA1, NDA2 and NDA3 havesubstantially the same shape and function as those of the cross-sectionstructure in the fourth non-display area NDA4. Therefore, the fourthnon-display area NDA4 will be described as a representative example, andredundant descriptions of the first, second and third non-display areasNDA1, NDA2 and NDA3 will be omitted.

One of the features of the display device DSP of the present embodimentis that a bypass area (contact area) BA in which the first alignmentfilm AL1 directly contacts the fourth insulating film 14 is provided inthe non-display area NDA.

As shown in FIG. 3, the fourth insulating film 14 has a groove 40 formedin such a manner as to surround the display area DA. The groove 40 canbe formed by removing the fourth insulating film 14 by full-toneprocessing, for example. The fourth insulating film 14 is divided into aperipheral portion 41 and a central portion 42 by the groove 40. Anupper surface 41A and a side surface 41N of the peripheral portion 41are covered with the fifth insulating film 15 which is impervious towater. The fifth insulating film 15, which covers the peripheral portion41, and the groove 40 cut out moisture entering from the peripheralportion 41 and prevent moisture from entering the central portion 42.

The display device DSP further includes a spacer PS1 and a spacer PS2for regulating the gap between the first substrate SUB1 and the secondsubstrate SUB2. The spacer PS1 has the shape of a frame, for example,and is arranged on the upper surface 41A of the peripheral portion 41 ofthe fourth insulating film 14. The spacer PS1 prevents the fluidizedsealant 3 from spreading outside from the spacer PS1 when the firstsubstrate SUB1 and the second substrate SUB2 are attached to each otherby the sealant 3.

The spacer PS2 is formed in the sealant 3 on the second substrate SUB2and projects toward the first substrate SUB1 in a column-like manner.The color filter layer 22 in the non-display area NDA overlaps thespacers PS1 and PS2 in planar view. The color filter layer 22 regulatesthe gap between the first substrate SUB1 and the second substrate SUB2together with the spacer PS1 and the spacer PS2.

In the present embodiment, the fifth insulating film 15 is formedbetween the first alignment film AL1 and the fourth insulating film 14in the display area DA. On the other hand, the fifth insulating film 15is not formed between the first alignment film AL1 and the fourthinsulating film 14 in the bypass area BA located in the non-display areaNDA. The first alignment film AL1 and the fourth insulating film 14directly contact each other in the bypass area BA.

In the example shown in FIG. 3, the bypass area BA is located on theinner side (on the display area DA side) from the groove 40 which cutsout moisture, and has the shape of a ring which surrounds the displayarea DA. The bypass area BA is not necessarily continuous but may bepartially discontinuous around the display area DA. The bypass area BAshould preferably include an inner bypass area BAin. When attention isfocused on the vicinity of the boundary between the liquid crystal layerLC and the sealant and if an area on the inner side from the sealant 3and on the outer side from the display area DA is assumed to be aboundary area NDAin, the inner bypass area BAin is an area in which theboundary area NDAin and the bypass area BA overlap each other in planarview.

In the display device DSP of the present embodiment having theabove-described structure, since the first alignment film AL1 contactsthe fourth insulating film 14 formed of an organic insulating film, themoisture of the first alignment film AL1 can dissipate into the fourthinsulating film 14.

FIG. 4 is a sectional view of a comparative example of the presentembodiment. If the bypass area BA is not formed as in the comparativeexample shown in FIG. 4, moisture will not be distributed from the firstalignment film AL1 to the fourth insulating film 14. In the comparativeexample shown in FIG. 4, when the display device DSP is left in hot andhumid conditions for a long time, external moisture entering from thesealant 3 and the first alignment film AL1 may go beyond the groove 40and reach the display area DA.

In the display area DA, if a reduction of volume resistivity of theliquid crystal layer LC is caused by the entering of moisture, theelectric charge of the liquid crystal layer LC flows to the firstalignment film AL1, and this promotes the voltage reduction of theliquid crystal layer LC. In association with this voltage reduction, thebrightness of an image displayed in the display area DA decreases incycles, that is, flicker occurs. The flicker cycle is long in theabove-described low frequency driving. Further, since the rewrite cycleof the voltage of the pixel electrode PE is long, the voltage reductionof the liquid crystal layer LC becomes large. Therefore, flicker tendsto be more noticeable in the low frequency driving mode as compared tothe normal driving mode.

On the other hand, the display device of the present embodiment shown inFIG. 3 can distribute and dissipate the moisture entering the firstalignment film AL1 into the fourth insulating film 14. Therefore, themoisture entering through the interior of the first alignment film AL1and reaching the display area can be reduced, and flicker can beprevented, accordingly.

If the first alignment film AL1 is formed of polyimide resin and thefourth insulating film 14 is formed of acrylic resin, the firstalignment film AL1 and the fourth insulating film 14 can contain aboutthe same amount of moisture per unit volume. The fourth insulating film14 according to the present embodiment is ten or more times thicker thanthe first alignment film AL1 and can sufficiently absorb the moisture ofthe first alignment film AL1. In the example shown in FIG. 3, the fourthinsulating film 14 is 30 times thicker than the first alignment filmAL1.

Meanwhile, the sealant 3 is formed of an organic material and is thusslightly pervious to water. Since the liquid crystal molecules of theliquid crystal layer LC are hardly pervious to water, the moistureentering the sealant 3 is absorbed by the first alignment film AL1. Whenthe display device DSP does not have the inner bypass area BAin, even ifall the moisture entering through the edge surface of the firstalignment film AL1 from the outside dissipates into the fourthinsulating film 14, the volume resistivity of the liquid crystal layerLC and the first alignment film AL1 in the display area DA may begradually reduced by the moisture from the sealant 3.

On the other hand, in the present embodiment, the display device DSP hasthe inner bypass area BAin, and the first alignment film AL1 and thefourth insulating film 14 contact each other in the boundary area NDAinlocated on the inner side from the sealant 3 and on the outer side fromthe display area DA. In the present embodiment, the moisture enteringthe first alignment film AL1 from the sealant 3 can also dissipate intothe fourth insulating film 14 in the inner bypass area BAin. Therefore,the moisture absorption of the first alignment film AL1 in the displayarea DA can be prevented regardless of the material of the sealant 3.

Meanwhile, the filth insulating film 15 formed of an inorganicinsulating film is inferior to the fourth insulating film 14 formed ofan organic insulating film in adhesiveness with reaped to the firstalignment film AL1. The present embodiment can also improve the adhesivestrength between the first alignment film AL1 and the fourth insulatingfilm 14 in the vicinity of the sealant 1.

In addition, the present embodiment can provide various otheradvantages.

Next, display devices according to the second and third embodiments willbe described. A structure having the same or a similar function as thestructure described in the first embodiment will be denoted by the samereference number and will be referred to the corresponding descriptionin the first embodiment, and detailed description thereof will beomitted. Further, structures other than those described below are thesame as those of the first embodiment.

Second Embodiment

The display device DSP of the second embodiment will be described withreference FIG. 5. FIG. 5 is a sectional view of the display device DSPof the second embodiment. As shown in FIG. 5, the display device DSP ofthe second embodiment differs from the first embodiment in that atransparent conductive film TC is further formed in the non-display areaNDA.

An example of the transparent conductive film TC formed in thenon-display area NDA is the trap electrode TE. The transparentconductive film TC may serve as an electric filed shield which mitigatesthe impact of an electromagnetic force from the outside, etc. In theexample shown in FIG. 5, the scan driver GD2 and the transparentconductive film TC partially overlap each other in planar view. Thetransparent conductive film TC may entirely overlap the scan driver GD2instead. In this case, the impact of an electric field from the scandriver GD2 on the liquid crystal layer LC and the impact of anelectromagnetic force from the outside on the scan driver GD2 can beprevented. Similarly, other circuits such as the scan driver GD1 and theimage driver SD may partially or entirely overlap the transparentconductive film TC in planar view.

The transparent conductive film TC has the shape of a ring whichsurrounds the display area DA, for example. The transparent conductivefilm TC may not be formed in one or some of the first, second, third andfourth areas NDA1, NDA2, NDA3 and NDA4. Further, the transparentconductive film TC may be formed discontinuously in the first, second,third and fourth non-display areas NDA1, NDA2, NDA3 and NDA4.

The transparent conductive film TC can be formed together with one ofthe pixel electrode PE and the common electrode CE, which aretransparent conductive films formed in the display area DA, in the samemanufacturing process. The transparent conductive film TC is formed onthe fourth insulating film 14 and is covered with the first alignmentfilm AL1. Since the transparent conductive film TC is less pervious towater than the fourth insulating film 14, the distribution of moisturefrom the first alignment film AL1 to the fourth insulating film 14 isprevented in an area in which the transparent conductive film TC isformed.

The display device DSP of the second embodiment has the bypass area BAin which the fifth insulating film 15 is not formed in the non-displayarea NDA, similarly to the firth embodiment. The bypass area BA includesthe inner bypass area BAin. In the second embodiment, the sealant 3includes a first area 31, a second area 32, a third area 33 and a fourtharea 34.

The first area 31 is located on the inner side of the sealant 3 (thedisplay area DA side). The first alignment film AL1 contacts thetransparent conductive film TC in the first area 31. The second area 32is located on the outer side from the first area 31. The first alignmentfilm AL1 contacts the fourth insulating film 14 in the second area 32.

The third area 33 is located on the outer side from the second area 32.In the third area 33, the first alignment film AL1 contacts the fifthinsulating film 15 formed on the upper surface 41A and the side surface41N of the peripheral portion 41 of the fourth insulating film 14. Inthe example shown in FIG. 5, the sealant 3 further includes the fourtharea 34 between the second area 32 and the third area 33. The fourtharea 34 overlaps the groove 40 formed in the fourth insulating film 14in planar view. The first alignment film AL1 contacts the thirdinsulating film 13 in the fourth area 34.

In the second embodiment, although the transparent conductive film TC isformed in part of the bypass area BA (for example, the first area 31 ofthe sealant 3), the transparent conductive film TC is not formed atleast in the most part of the second area 32 and the inner bypass areaBAin. That is, the first alignment film AL1 and the fourth insulatingfilm 14 directly contact each other in the most part of the second area32 and the inner bypass area BAin. According to the second embodiment,the reduction of electrical resistivity of the first alignment film AL1can be prevented by dissipating moisture entering the first alignmentfilm AL1 into the fourth insulating film 14, similarly to the firstembodiment.

The fifth insulating film 15 has low adhesiveness with respect to thesealant 3 and the fourth alignment film AL1 as compared to thetransparent conductive film TC. In such a structure where thetransparent conductive film TC is added to the comparative example shownin FIG. 4, to improve the adhesiveness with respect to the firstalignment film AL1, the transparent conductive film TC may be formed inthe first, second, third and fourth areas 31, 32, 33 and 34 of thesealant 3. In such a structure, even if the filth insulating film 15 isremoved, the distribution of moisture will be prevented by thetransparent conductive film TC. In view of this, not only the bypassarea BA in which the fifth insulating film 15 is not formed, but alsothe second area 32 in which the transparent conductive film TC is notformed are provided on purpose in the second embodiment. Therefore, theadhesiveness between the first alignment film AL1 and the fourthinsulating film 14 below the sealant 3 can be improved, and a moisturedistribution path from the first alignment film AL1 to the fourthinsulating film 14 can be secured.

Third Embodiment

The display device DSP of the third embodiment will be described withreference to FIG. 6. The third embodiment differs from the firstembodiment that the fourth insulating film 14 has a regulating portion60 in the boundary area NDAin located on the inner side from the sealant3 and on the outer side from the display area DA. The regulating portion60 includes a recess 61 and a projection 62. Although three recesses 61and two projections 62 between the adjacent recesses 61 are provided inthe example shown in FIG. 6, the number of the recesses 61 and thenumber of the projections 62 included in the regulating portion 60 arenot limited to these numbers. Further, the regulating portion 60 mayonly include one of the recess 61 and the projection 62.

The recess 61 extends along the sides E1, E2, E3 and E4 and is recessedfrom a surface 14A of the fourth insulating film 14, for example. Therecess 61 can be formed by multi-tone processing such as half-toneprocessing, for example. A portion 14B of the fourth insulating film 14in the thickness direction which is not removed by the multi-toneprocessing remains between the bottom of the recess 61 and the thirdinsulating film 13.

The projection 62 is formed between the adjacent recesses 61, forexample. In the example shown in FIG. 6, the top of the projection 62 islocated at the same height as that of the surface 14A of the fourthinsulating film 14, and the projection 62 is projecting when viewed fromthe recess 61. The top of the projection 62 may be lower than thesurface 14A. Alternatively, the recess 61 may not be formed, but onlythe projection 62 projecting from the surface 14A of the fourthinsulating film 14 may be formed. The projection 62 higher than thesurface 14A of the fourth insulating film 14 can be formed together withthe spacer PS1 in the same manufacturing process, for example.

In the example shown in FIG. 6, the top of the projection 62 is coveredwith the transparent conductive film TC such as the trap electrode TE.At the time of printing the composition of the first alignment film AL1,the composition of the first alignment film AL1 falls from theprojection 62 to the recess 61. As a result, the first alignment filmAL1 is divided in the regulating portion 60. The wettability of thetransparent conductive film TC with respect to the composition of thefirst alignment film AL1 is lower man the wettability of the fourthinsulating film 14 with respect to the composition of the firstalignment film AL1 When the projection 62 is covered with thetransparent conductive film TC, the transparent conductive film TC shedsthe composition of the first alignment film AL1, and therefore the firstalignment film AL1 will be more clearly divided.

According to the third embodiment, similarly to the first and secondembodiments, the moisture absorption of the first alignment film AL1 canbe prevented by dissipating the moisture entering from the edges of thefirst alignment film AL1 into the fourth insulating film 14. Further,the first alignment film AL1 is divided by the regulating portion 60 inthe third embodiment. The first alignment film AL1 in the display areaDA, and the edges of the first alignment film AL1 facing the outside arenot continuous with each other. Therefore, the moisture from the edgescan be cutout, and the moisture absorption of the first alignment filmAL1 in the display area DA can be prevented.

The sealant 3 is slightly pervious to water. When the regulating portion60 is formed in an area overlapping the sealant 3, even if moisture iscut out by the regulating portion 60, moisture may still enter from thesealant 3. In the present embodiment, the regulating portion 60 isformed in the boundary area NDAin, and therefore the regulating portion60 can cut out moisture on the inner side from the sealant 3.

In the regulating portion 60 according to the third embodiment, therecess 61 is formed not by the full-tone processing but by the half-toneprocessing. Therefore, even if the regulating portion 60 is formeddirectly above the drive circuits (the scan drivers GD1 and GD2, etc.),the third insulating film 13 will not be exposed. Even if moisture isdistributed from the first alignment film AL1 to the recess 61 of theregulating portion 60, the third insulating film 13 is covered with theportion 14B of the fourth insulating film 14 in the thickness direction,and the impact of the moisture can be reduced by the drive circuits.Since the drive circuits and the regulating portion 60 can be arrangedin such a manner as to overlap each other in the narrow non-display areaNDA, the design flexibility of the layout of the regulating portion 60and the drive circuits can be increased. As a result, the frame of thedisplay panel PNL can be narrowed.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

For example, the first polarizer PL1 may be omitted by using theillumination device BL which emits polarized light. For example, thecolor filter layer 22 may be formed not on the second substrate SUB2 buton the first substrate SUB1.

What is claimed is:
 1. A display device comprising: a first substrate; asecond substrate facing the first substrate; a sealant which attachesthe first substrate and the second substrate to each other; a liquidcrystal layer arranged between the first substrate and the secondsubstrate; an organic insulating film provided on the first substrate;an alignment film provided on the first substrate and contacting theliquid crystal layer; and an inorganic insulating film provided on thefirst substrate and located between the alignment film and the organicinsulating film, wherein a part of the inorganic insulating film isremoved in an area overlapping with the sealant and the organicinsulating film.
 2. The display device of claim 1, wherein the firstsubstrate and the second substrate have a display area which displays animage, and the alignment film contacts the organic insulating film inthe area in which the part of the inorganic insulating film is removed.3. The display device of claim 1, wherein the first substrate and thesecond substrate have a display area which displays an image, and thealignment film does not contact the organic insulating film and contactsthe inorganic insulating film in the display area.
 4. The display deviceof claim 2, further comprising: a transparent conductive film formed onthe first substrate and contacting the alignment film and the inorganicinitiating film in the display area, wherein the sealant has a firstarea, and a second area located on an outer side from the first area,and the alignment film contacts the transparent conductive film in thefirst area, and contacts the organic insulating film in the second area.5. The display area of claim 3, further comprising: a transparentconductive film formed on the first substrate and contacting thealignment film and the inorganic insulating film in the display area,wherein the sealant has a first area, and a second area located on anouter side from the first area, and the alignment film contacts thetransparent conductive film in the first area, and contacts the organicinsulating film in the second area.
 6. The display device of claim 4,wherein the sealant further comprises a third area on an outer side fromthe second area, and the alignment film and the organic insulating filmcontact the inorganic insulating film in the third area.
 7. The displaydevice of claim 5, wherein the sealant further comprises a third area onan outer side from the second area, and the alignment film and theorganic insulating film contact the inorganic insulating film in thethird area.
 8. The display device of claim 4, wherein a voltage isapplied to the transparent conductive film in the second area.
 9. Thedisplay device of claim 5, wherein a voltage is applied to thetransparent conductive film in the second area.
 10. The display deviceof claim 6, wherein a voltage is applied to the transparent conductivefilm in the second area.
 11. The display device of claim 7, wherein avoltage is applied to the transparent conductive film in the secondarea.
 12. The display device of claim 2, wherein the organic insulatingfilm has a regulating portion on an inner side from the sealant and onan outer side from the display area, and the regulating portion includesa recess or a projection extending in a predetermined direction.
 13. Thedisplay device of claim 3, wherein the organic insulating film has aregulating portion on an inner side from the sealant and on an outerside from the display area, and the regulating portion includes a recessor a projection extending in a predetermined direction.
 14. The displaydevice of claim 4, wherein the organic insulating film has a regulatingportion on an inner side from the sealant and on an outer side from thedisplay area, and the regulating portion includes a recess or aprojection extending in a predetermined direction.
 15. The displaydevice of claim 5, wherein the organic insulating film has a regulatingportion on an inner side from the sealant and on an outer side from thedisplay area, and the regulating portion includes a recess or aprojection extending in a predetermined direction.
 16. The displaydevice of claim 6, wherein the organic insulating film has a regulatingportion on an inner side from the sealant and on an outer side from thedisplay area, and the regulating portion includes a recess or aprojection extending in a predetermined direction.
 17. The displaydevice of claim 7, wherein the organic insulating film has a regulatingportion on an inner side from the sealant and on an outer side from thedisplay area, and the regulating portion includes a recess or aprojection extending in a predetermined direction.
 18. The displaydevice of claim 12, wherein the first substrate includes an insulatingbase and a drive circuit for displaying an image in the display area,and the drive circuit is provided between the insulating base and theregulating portion, and overlaps the regulating portion in planar view.19. The display device of claim 13, wherein the first substrate includesan insulating base, and a drive circuit for displaying an image in thedisplay area, and the drive circuit is provided between the insulatingbase and the regulating portion, and overlaps the regulating portion inplanar view.
 20. The display device of claim 2, wherein a framefrequency of the image displayed in the display area is 40 Hz or less.